package com.itheima.reggie.filter;
import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
 * 检查用户是否已经完成登录
 */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        //测试： 获取当前线程ID,并输出
        long id = Thread.currentThread().getId();
        log.info("线程id为：{}",id);

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();// /backend/index.html
            //来个日志看看URI情况
        log.info("拦截到请求：{}",requestURI);
        //将需要放行的路径放到数组，方便统一处理
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };
        //2、判断本次请求是否需要处理  此方法就是比较资源路径是否包含放行路径 为true则放行
        boolean check = check(urls, requestURI);

        //3、如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4、判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee") != null){  //能获取到存到session域中的id 不为null
            System.out.println("================员工登录判断=============");
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

            //如果已经登录，放行前，对ThreadLocal进行赋值 先取出对象(也就是id)
            Long ThreadLocalId = (Long) request.getSession().getAttribute("employee");
            //复制给线程上的局部变量ThreadLocal
            BaseContext.setCurrentId(ThreadLocalId);


            filterChain.doFilter(request,response);
            return;
        }

        //4-2、判断移动端登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            System.out.println("================移动登录判断=============");
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        log.info("用户未登录");
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;

    }


    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            /*路径匹配器.方法match    方法match 里面的doMatch方法就是在比较  返回一个boolean
protected boolean doMatch(String pattern, @Nullable String path, boolean fullMatch,
			@Nullable Map<String, String> uriTemplateVariables)
             */
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
